EVALUATION OF HEMATOLOGICAL PROFILES AND THEIR INFLUENCE ON TREATMENT OUTCOMES IN NEWLY DIAGNOSED PULMONARY TUBERCULOSIS PATIENTS IN WESTERN KENYA

Abstract

Pulmonary tuberculosis (PTB) is among the leading infectious diseases globally in terms of morbidity and mortality with an estimated 1.3 million people having succumbed to the disease in 2022 despite the availability of effective anti-tubercular treatment. In Kakamega County, mortality is estimated to be 10.8%, which is double the national target of <5% for TB-related deaths. The potential factors contributing to this persistently high mortality rate are not fully understood. To date, there are no reliable prognostic markers for PTB monitoring. The objectives of this study were to evaluate the hematological profiles of newly diagnosed PTB patients, changes during the course of treatment and their influence on treatment outcomes. The study was conducted at Kakamega County Teaching and Referral Hospital in Kakamega County. The study adopted a prospective longitudinal study design and used convenience sampling to recruit 55 participants for both the PTB and control groups. The sample size was determined by G-power sample calculation software with a power of 0.80, alpha of 0.05 and a large effect size of 0.5. Venous blood was collected for hematological profile analysis in both the PTB and control group. However, for the PTB group, hematological profile analysis was done at diagnosis, at months 2 and 5 of treatment. Microscopy analysis of sputum smears at months 2 and 6 was used to monitor for sputum smear conversion and outcomes, respectively. Data were analyzed using Chi-square, Mann-Whitney U test, Kruskal-Wallis test with a post hoc of Dunn’s multiple comparisons test and multivariate logistic regressions where applicable in SPSS version 29.0 and Graph Pad prism version 6.0. Males were 80% (n=44) in the PTB group and 81.8% (n=45) in the control group. At diagnosis, the PTB group had a significantly lower median RBC count compared to controls (4.79x106/µL vs 5.2x106/µL, P=0.001). Similarly, relative to the control group the PTB group had lower HGB levels (12.8g/dL vs 14.3g/dL), HCT (37.9% vs 42.05%), mean platelet volume (8.9fL vs 10.5fL) and platelet distribution width (10.4fL vs 13.0fL) (P<0.001). Further, the PTB group had significantly higher median WBC counts (6.82x103/µL vs 4.60x103/µL), RDW-CV% (12.8 vs 11.9), RDW-SD (42.3fL vs 40.4fL) and median platelet count (314.0x103/µL vs 237.0x103/µL) (P<0.001) compared to the control group. Peripheral blood film analysis at diagnosis revealed normocytic normochromic anemia was predominant at 54.5% (n=30) followed by microcytic hypochromic anemia in 38.2% (n=21) of the PTB patients. Controls had normocytic normochromic anemia and microcytic hypochromic anemia at 90.9% (n=50) and 3.6% (n=2), respectively. Comparison of hematological profiles for PTB patients at diagnosis, month 2 and month 5 revealed a significant decrease in WBC counts, neutrophil counts and platelet counts. Low lymphocyte count, low HGB, high WBC count and high Platelet count were significantly associated with increased odds of having a positive sputum smear post-intensive phase of treatment (P<0.001). Normal counts for WBC, MCV, MCH, MCHC, RDW-CV% and platelet showed a statistically significant association with treatment outcomes among PTB patients at month 6 (P<0.05). Therefore, newly diagnosed PTB patients at KCTRH present with deranged hematological profiles, with abnormal peripheral features such as microcytic hypochromic anemia. The hematological changes following treatment have significant effects on sputum smear conversion suggesting the need for routine monitoring of their hematological profiles. The study recommends that the hematological profiles of newly diagnosed PTB patients be monitored a diagnosis and during course of treatment so as to tailor patient specific treatment approaches for better clinical outcomes.